Combination pickling-rolling mill

ABSTRACT

A mill which combines the processes of pickling hot band and subsequent cold rolling. The pickled strip is passed from the pickling line directly to a tandem cold rolling mill without any intervening coiling thereof. The combination mill is adapted to operate as a combination pickling-rolling mill, for fully continuous rolling of pickled coils and for conventional batch type rolling.

United States Patent 11 1 [4 Nov. 11, 1975 Eibe I COMBINATION PICKLING-ROLLING MILL [75 Inventor: Werner W. Eibe, Pittsburgh, Pa. [73] Assignee: Blaw-Knox Foundry & Mill Machinery, Inc., Pittsburgh, Pa. {22] Filed: Sept. 4, 1974 [21] Appl. No: 503,055

[52] US. Cl. 72/39; 72/200; 72/228;

- 72/202 [51] Int. Cl. B21B 45/04; B21B 45/06 [58] Field of Search 72/38, 39, 40, 200, 201, 72/202, 227, 228, 230, 231; 134/64, 122, 137

[56] References Cited UNITED STATES PATENTS 1.380.437 6/1921 Sundh 134/122 1,412,979 4/1922 Sundh V 72/39 1,819,764 8/1931 Blecker 72/39 2,960,963 11/1960 Shelton..... 134/64 3,052,244 9/1962 Gley 134/64 3,060,945 10/1962 Spenle 72/39 R7,004 3/1876 Lauth 72/39 LINE ENTRY SECWITH LEVELER FINE CUT SHEAR WELDE 5 CONVENTIONAL ELIEF NOTCHERK .mu. 2 NTFIV sag fye sumo TANDEM cow MILL scno FOREIGN PATENTS OR APPLICATIONS 143,295 5/1961 U.S.S.R 134/64 OTHER PUBLICATIONS The Making, Shaping and Treating of Steel, US. Steel, 7th Edition, 1957, pp. 598-599, 638.

Primary Examiner-C. W. Lanha'm Assistant E.\'aminerE. M. Combs Attorney, Agent, or Firnz-Smith, Harding, Earley & Follmer [57] ABSTRACT A mill which combines the processes of pickling hot band and subsequent cold rolling. The pickled strip is rolling.

21 Claims, 1 Drawing Figure DIVIDING SHEARQ TENSION PEEL N SEC ION COIL DELIVERY READY FOR INSPECTION &

ROLL CHANGE W STRAPPINGfi MATCH LINE A 97 98 VARIA er. a

/-SCALE REMOVALIQTRIMMER SEC MATCH LINE A m COMBINATION PICKLING-ROLLING MILL BACKGROUND OF THE INVENTION In the past, the processes of pickling hot band and subsequent cold rolling have been practiced as separate processes. After the pickling process, the pickled strip is coiled and stored. Subsequently, the stored coils are delivered to a cold rolling mill for rolling the strip to the desired thickness.

In addition to the loss of production, the separate operation of the processes of pickling hot band and subsequent cold rolling thereof results in a considerable duplication of equipment. In addition, there is an excessive use of building and floor space and an increased labor force is required because of the equipment duplication. Expenses of operation are also increased because of excessive handling and the inventory of the coils between the separate operations.

The disadvantages set forth above could be overcome bythe provision of a mill in which the processes of pickling and cold rolling are combined.

SUMMARY OF THE INVENTION It is the general object of this invention to provide a combination mill in which the processes of pickling and cold rolling are combined in a single operation and in which the pickled strip is passed directly to a tandem rolling mill without any intervening coiling thereof.

Another object of the invention is to provide a combination mill of the indicated type which, in addition to operation as a combination pickling-rolling mill, is operable for the pickling of strip, for the fully continuous rolling of pickled coils and for conventional batch type rolling.

The combination of pickling and rolling into a single operation has not been considered to be practical in the past because of the difficulty in matching production rate and utilization time between the two facilities. With the development of a highly efficient fully continuous /6 stand tandem cold mill such as the one described in my application Ser. No. 503,056, filed Sept. 4, 1974, the net utilization time ofa tandem rolling mill can be brought up to the level of a well designed-high production pickle line. It is noted that most of the equipment needed for the entry end of a fully continuous rolling mill is a duplicateof that type of equipment now used at the entry and delivery section of a modern pickle line. In the past devices it was uneconomical to produce pickled, oiled, and strapped coils which have to be handled and stored for a later rehandling and processing through a tandem mill. However, by the provision of a combination pickling-rolling mill in accordance with the invention these duplications and uneconomical storing procedures are obviated.

The combination pickling-rolling mill in accordance with the invention has a number of compatible conditions between the two processes, namely, (1) the production is on the same level, (2) the exit pickling and entry mill speeds are close, (3) the utilization time of the two processes is matched, (4) the service life of the equipment contacting the strip is balanced (5) the pickled strip comes dry and clean for entering the mill, and (6) the strip has time to cool to a reasonable temperature before arriving at the first stand of the tandem mill.

Furthermore, the combination pickling-rolling mill in accordance with the invention achieves a high utilization by the flexibility of the layout. The mill in accordance with the invention has the possibility of using the pickling line alone or of using the mill alone. Also, it can provide fully continuous operation of the mill without the pickling line.

The combination pickling-rolling mill in accordance with the invention achieves considerable saving by reason of combining equipment which was previously duplicated in the separate processes. By reason of the use of combined equipment, capital expenditure savings in mechanical and electrical equipment is achieved, building and floor space is saved, coil inventory is eliminated, and labor costs are reduced.

In accordance with a further aspect of the invention, the total length of the pickling tank section is increased about 25 percent. This permits a greater speed increase which is especially desired for some sheet gauges. Moreover, a coarse pickling speed adjustment is made available by mechanically changing the total strip immersion length and/or the scale breaking technique.

The capital expenditure savings of a combination pickling-rolling mill over a comparable two process system is substantial. Combining the mechanical and electrical equipment should save about 18 percent. Also, the savings in buildings and floor space would be considerable. Furthermore, a permanent operational cost saving is a greatly reduced labor force due to the elimination of equipment duplication. Finally, less handling and no, or only a small, inventory of coils between the normally separation operation results in substantial savings.

BRIEF DESCRIPTION OF THE DRAWING The single FIGURE of the drawing is a side elevation of a combination pickling-rolling mill in accordance with the invention partly in diagrammatic form.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawing, there is shown a combination pickling-rolling mill in accordance with the invention in which there is provided a 5/6 stand tandem cold rolling mill section such as the one shown in my application Ser. No. 503,056, filed Sept. 4, 1974. The tandem cold roll mill comprises six mill stands I, 2, 3, 4, 5 and 6 of the conventional four-high type. A three roll bridle unit 10 is located adjacent the entry end of mill stand 1 and serves to control the tension of the strip delivered thereto. At the exit end of the mill, the strip is delivered from the mill stand 6 to a dividing, shear and tension reel section which comprises a pinch roll 12, a shear l4 and a pair of tension reels l6 and 18. Adjacent the dividing, shear and tension reel section is a coildelivery, inspection and strapping section which comprises a coil transfer car 22, a bander 24, and a delivery conveyor 26.

The 5/6 stand tandem cold milldescribed in said priormentioned application comprises one more mill stand than is required by the mill to achieve the rolling of strip in accordance with the pass schedules for which the mill is designed. By reason of the provision of an additional mill stand, there is always a mill stand which can be substituted for a mill stand which is to have its rolls changed. The mill stands are designed so that each mill stand can achieve the rolling action of a preceding upstream mill stand. To this end, the mill stands are designed such that each can operate throughout most of the speed range of an adjacent mill stand whereby a mill stand can be taken out of the rolling line for roll changing without interrupting the rolling action of the mill by adjusting the remaining operative mill stands and a substitute mill stand to achieve the necessary rolling conditions. This type of mill stand increases the utilization time of the mill by saving the downtime resulting from a roll changing operation.

To the immediate left of bridle unit is a conventional mill entry section which comprises a payoff reel 30, a coil preparation car 31, and a coil end preparation station 32.

To the left of the conventional mill entry section is a group of equipment for treating a pickled strip which is to be coiled, such group comprising a strip oiler 34, a pair of pinch rolls 36, a shear 38 and a pair of guide pinch rolls 39. The pinch rolls 39 are adapted to be tilted to a position to guide a pickled strip to a tension reel 40 for coiling as will be described more fully hereafter.

To the left of the strip oiler 34 is a pinch roll unit 44 which is adapted to receive strip from below by way of a three roll bridle unit 46 and to receive strip from above by way of a guide roller 48.

To the left of the pinch roll unit 44 is a line entry section which comprises a pair of payoff reels 50 and 52, a leveler 54 and a leveler-pinch roll unit 56, a fine cut shear 58, a welder 60, and a relief notcher 62. At the left end of the line entry section is a three roll bridle unit 64 which is cut through the center by the match line A" shown in the drawing.

To the left of the line entry section is a scale removal and trimmer section which comprises an entry bridle unit 66, a mill stand comprising two sets of rolls 68 and 70 for scale breaking and skin passing, a three roll bridle unit 72, two pairs of rotary side trimming shears 74 and 76 and two pairs of scrap choppers 78 and 79. At the exit end of the scale removal and trimmer section there is provided a two roll bridle unit 80.

To the left of the scale removal and trimmer section is a looper 82 which receives strip from the bridle unit 80.

To the left of the looper 82 is a variable speed pickling section which comprises an entry bridle unit 84 which receives the strip entering the pickling section from looper 82 and delivers the strip to a three section pickling tank 86. The top level of the pickling solution is indicated at 88. The strip enters the solution in the pickling tank 86 by passage across a plurality of rollers 90 which hold the strip above the level of the pickling solution. The rollers 90 are movable from a retracted solid line position to an extended dashed line position as shown in the drawing to vary the location at which the strip is delivered into the pickling solution. The strip is supported at intermediate locations in the pickling tank 86 by a pair of supports 92 and leaves the pickling solution by passage over a plurality of rollers 94 which hold the strip above the solution level 88. The rollers 94 are movable from a retracted solid line position to an extended dashed line position as shown in the drawing to vary the location at which the strip passes out of the pickling solution. Thus, in the same manner as the rollers 90, the rollers 94 serve to vary the length of strip maintained in the pickling solution, whereby the pickling speed can be varied.

From the rollers 94, the pickled strip passes through a three section rinsing tank 96, squeegee rolls 97 which remove the pickling solution from the strip and a drying section 99. The strip then passes to a three roll bridle unit 98.

Located beneath the pickling tank 86 is a line entry looper, i.e., it serves as the entry looper for the pickle line. This looper is of conventional type and comprises three loop cars which ride on horizontal tracks and carry rollers 100 which are moved between the solid and dashed line positions during the delivery of accumulated strip as is conventional in the art. The line entry looper also comprises a pair of stationary rolls 102 and drum means 104 for controlling the movement of the movable rolls 100. Strip enters the line entry looper by being fed around a roller 106 from the bridle unit 64 and passes to the lowermost movable roll 100. The strip is delivered from the line entry looper by way of a pair of rolls 108 and 110 from which it is passed around a roll 112 to the entry bridle unit 66 for the scale removal and trimmer section.

To the left of the line entry looper is a line exit and mill entry looper which serves as the exit looper for the pickle line and as the entry looper for the 5/6 stand mill. The line exit and mill entry looper is of conventional type and comprises loop cars which are movable on horizontal tracks and carry three movable rollers 120 for movement between the solid and dashed line positions shown on the drawing. The looper comprises four stationary rollers 122 and drum means 124 for controlling movement of the movable rolls 120. The rolls 120 move from the dashed line position to the solid line position during the payout of accumulated strip as is conventional in the art. Strip is delivered to the uppermost stationary roll 122 of the line exit and mill entry looper from the exit bridle unit 98. Strip is delivered from this looper by way of the lowermost stationary roller 122 from which it passes beneath the line entry looper, the scale removal and trimmer section and the line entry section to the three roll bridle unit 46.

In the operation of the mill as a combination pickling-rolling mill, the strip is fed from a coil on payoff reel 50, for example, to the left as viewed in the drawing through the leveler 54 and the other elements of the line entry section to the three roll bridle unit 64 from which it passes around roller 106 to the bottom roll 100 of the line entry looper. It is noted that the main pass for the combination pickling'rolling mill is shown by the single arrow lines in the drawing. After passing through the line entry looper, the strip passes around rollers 108, 110 and 112 to the entry bridle unit 66 for the scale removal and trimmer section. The strip is then treated by one of the sets of rolls 68 or for scale breaking and skin passing. it is noted that only one of these rolls 68 and 70 is operable at a time, the other roll remaining ready to be changed while the first one is performing the scale breaking operation. After passing around the bridle unit 72, the strip passes through the trimming shears and choppers 74, 78, 76 and 79, which operate to trim the strip in preparation for pickling. The strip then passes from the exit bridle to the looper 82 from which the strip passes to the entry bridle 84 for the pickling section.

In the pickling section the strip passes over the top of rollers and into the pickling solution in the tank 86 at a desired location. The strip passes over the supports 92 and out of the pickling solution by passing onto the top of rollers 94. The rollers 90 and 94 are set to a predetermined position to control the point at which the strip enters and leaves the pickling solution. By this arrangement, even though the pickling time is about the same for most material, the speed of the strip passing through the pickling solution can be varied to precisely that desired for the strip being rolled. This permits a more accurate matching of the speed of the pickling line with that of the tandem rolling mill.

After passing through the mechanism for removing the solution from the strip, the strip passes through the bridle unit 98 and into the line exit and mill entry looper at the top stationary roll 122. From the bottom stationary roll 122 of this looper, the strip passes to the right to the bridle unit 46 and upwardly to the pinch rolls 44. From the pinch rolls 44 the strip passes to the right across the conventional mill entry section and into the entry bridle unit for the tandem rolling mill section. After being rolled at the mill stands of this section, the strip passes alternately to one of the tension reels l6 and 18 whereat the strip is coiled. The rolled coil is then transferred to the circumferential and eye bander 24 by the conveyor 26. From the bander 24, the rolled coil continues to move along the delivery conveyor 56 for removal as is conventional in the art. Some coils are taken off the conveyor 26 at random by the coil car 22 for inspection.

When all of the coil has passed off the reel 50 which is delivering the coil being rolled, the trailing end is joined to the beginning end ofa coil on the other payoff reel 52. The forward end of the coil on the payoff reel 52 is passed through the flattener 54 to the line entry section where it is joined with the trailing end of the coil just paid off from reel 50. During this coil switching procedure, which requires that the strip within the line entry section be stopped for a short while, strip is continued to be fed to the pickling section, and ultimately to the five/sixths stand tandem cold mill section, by the action of the line entry looper which delivers accumulated strip to entry bridle 66. Also, the line exit and mill entry looper is used to maintain the desired rate of supply of strip to the tandem cold mill which is slowed down for the purpose of switching. To this end, the line exit and mill entry looper is in the solid line position shown on the drawing and accumulates strip as the rolls 120 move to the right to the dashed line position as the looper is filled. This allows the strip to run at a steady speed through the pickling section. When the rolling mill subsequently accelerates from the reel switch speed to full speed, the rolls 120 will move to the left from the dashed to the solid line position to deplete the looper. A continuous supply of strip is maintained by alternately supplying coils from the payoff reels 50 and 52 and by joining in the line entry sectionthe trailing end of the coil being rolled to the beginning end of the new coil.

It will be apparent that in this mode of operation, pickled strip is delivered directly from the pickling line to the tandem cold mill section without any intervening coiling thereof.

It is noted that the layout of the mill in accordance with the invention is highly flexible so as to permit high utilization thereof. Thus, the mill can be operated as a pickling line alone if desired. Also, it can be used as a fully continuous rolling mill or a conventional rolling mill without the pickling line. This will be apparent by a consideration of FIG. 1 wherein there is shown in double arrow lines the alternate pass for continuous rolling of pickled coils and in triple arrow lines the pass for conventional batch type rolling.

This multiple pass design maintains the full working identity of either the mill or the pickling section in the event of a time consuming repair in either one of these sections.

In the operation of the mill for the fully continuous rolling of pickled coils, the operation is the same as that described above except that pickled coils are delivered from the reels 50 and 52 and the strip passes from the entry bridle 66 for the scale removal and trimmer section upwardly to the roller 49 and to the right to the roller 48 and downwardly into the pinch roll 44 from which it passes across the conventional mill entry section to the bridle unit 10 for passage to the rolling mill. Thus, the scale removal and trimmer section and the pickling section are bypassed.

In operation for conventional batch type rolling, the strip is delivered to the mill directly from a coil on the payoff reel 30, the strip having been prepared from the coil car 31 at the coil preparation station. When a previous coil has paid off reel 30, the coil car 31 is moved to the right so as to place the prepared coil onto the payoff reel 30. At the same time, the prepared front end is fed to the rolling mill. In this operation the use of bridle unit 10 is optional and can be bypassed if desired.

When the mill is operated as a pickling line alone, the strip is moved along the main pass line as described above except that after passing through the guide pinch rolls 39, the pickled strip is directed downwardly onto a tension reel 40 whereat it is coiled. During this mode of operation the shear 38 is used to trim the trailing end of the coil on reel 40.

It is thus apparent that the mill has a high degree of flexibility. Thus, if there is a breakdown in the rolling mill section, the mill can be operated to continue pickling. Also, if the pickling line has a breakdown or requires maintenance, fully continuous rolling can still be maintained. Moreover, if any equipment to the left of the conventional mill entry section should require maintenance or break down, the mill can still operate with conventional batch type rolling. Furthermore, if anything behind the entry bridle 66 for the scale removal and trimmer section should break down or require maintenance, fully continuous rolling can still be performed.

The arrangement and grouping of the mechanical equipment is also an improvement over the prior art. For example, the trimming shear group, including elements 74, 76, 78 and 79, as well as the pickled coil outlet equipment, including elements 34, 36, 38, 39 and 40, are placed at the same location as all the other equipment for performing operations associated with the pickle line. This is different from the prior art arrangements wherein such rolls were placed behind the pickle line. The arrangement in accordance with the invention groups all the mechanical equipment in the same place whereby the operators have easier access thereto.

Also, the pickle line is located at the extreme end of the combination mill. Thus, the fumes and other deleterious aspects of the pickle line are separated from the rest of the equipment of the mill.

I claim:

1. A combination pickling-rolling mill comprising a rolling mill section for the rolling of strip, a pickling section for the pickling of strip located on the entry side of said rolling mill section, means including a supply of strip to be pickled and rolled located between said pickling section and the entry end of said rolling mill section for feeding strip to be pickled and rolled from said strip supply to said pickling section in the direction away from said rolling mill section, and means for feeding strip from the exit end of the pickling section in the direction toward said rolling mill section directly to the entry end of said rolling mill section for rolling thereof without the intervening coiling of strip.

2. A combination pickling-rolling mill according to claim 1 wherein said means for feeding strip to the pickling section includes a pair of payoff reels, and means for alternately feeding strip from coils on said payoff reels to said pickling section.

3. A combination pickling-rolling mill according to claim 2 comprising a pickle line entry looper in the main pass line of the mill between the means for feeding strip to said pickling section and said pickle section for accumulating a length of strip.

4. A combination pickling-rolling mill according to claim 3 including a pickle line exit and mill line entry looper located in the main pass line of the mill between the exit of said pickling section and the entrance of said rolling mill.

5. A combination pickling-rolling mill according to claim 4 including means for joining the trailing end of a coil on one of said payoff reels with the beginning end ofa coil on the other of said payoff reels, said end joining means being located in the main pass line of the mill between said pair of payoff reels and said pickle line entry looper.

6. A combination pickling-rolling mill according to claim 5 wherein there is provided a scale removal and trimmer section located in the main pass line of the mill between said pickle line entry looper and said pickling section.

7. A combination pickling-rolling mill according to claim 6 wherein said scale removal and trimmer section comprises a pair of alternately operable rolls for scale breaking and skin passing.

8. A combination pickling-rolling mill according to claim 7 wherein said scale removal and trimmer section includes two pairs of alternately operable rotary side trimming shears and two pairs of alternately operable scrap choppers.

9. A combination pickling-rolling mill comprising a rolling mill section for the rolling of strip, a pickling section for the pickling of strip, means for feeding strip to be pickled and rolled to said pickling section, means for feeding strip from the exit end of the pickling section directly to the entry end of said rolling mill section for rolling thereof without the intervening coiling of strip, said means for feeding strip to the pickling section including a pair of payoff reels and means for alternately feeding strip from coils on said payoff reels to said pickling section, a pickle line entry looper in the main pass line of the mill between the means for feeding strip to said pickling section and said pickling section for accumulating a length of strip, a pickle line exit and mill line entry looper located in the main pass line of the mill between the exit of said pickling section and the entrance of said rolling mill, means for joining the trailing end of a coil on one end of said payoff reels with the beginning end ofa coil on the other end of said payoff reels, said end joining means being located in the main pass line of the mill between said pair of payoff reels and said pickle line entry looper. and means for feeding strip in an alternate pass line from the exit end of said pickle line entry looper and bypassing said pickling section to said rolling mill section whereby fully continuous rolling is performed by the passage of strip through said alternate pass line.

10. A combination pickling-rolling mill comprising a rolling mill section for the rolling of strip, a pickling section for the pickling of strip, means for feeding strip to be pickled and rolled to said pickling section, means for feeding strip from the exit end of the pickling section directly to the entry end of said rolling mill section for rolling thereof without the intervening coiling of strip, said means for feeding strip to the pickling section including a pair of payoff reels and means for alternately feeding strip from coils on said payoff reels to said pickling section, a pickle line entry looper in the main pass line of the mill between the means for feeding strip to said pickling section and said pickling section for accumulating a length of strip, a pickle line exit and mill line entry looper located in the main pass line of the mill between the exit of said pickling section and the entrance of said rolling mill, means for joining the trailing end of a coil on one end of said payoff reels with the beginning end ofa coil on the other end of said payoff reels, said end joining means being located in the main pass line of the mill between said pair of payoff reels and said pickle line entry looper, a tension reel means, and means for diverting strip, which is being fed from the line exit and mill entry looper toward said roll ing mill section, to said tension reel means for the coiling of pickled strip.

11. A combination pickling-rolling mill according to claim 10 including means for treating strip delivered to said tension reel means.

12. A combination pickling-rolling mill according to claim 9 including a conventional mill entry section which comprises a third payoff reel located adjacent said the entry end of said rolling mill section and means for feeding strip from a coil on said third payoff reel directly to said rolling mill for conventional batch-type rolling.

13. A combination pickling-rolling mill comprising a rolling mill section for the rolling of strip, a pickling section for the pickling of strip, means for feeding strip to be pickled and rolled to said pickling section, means for feeding strip from the exit end of the pickling section directly to the entry end of said rolling mill section for rolling thereof without the intervening coiling of strip, said means for feeding strip to the pickling section including a pair of payoff reels and means for alternately feeding strip from coils on said payoff reels to said pickling section, a pickle line entry looper in the main pass line of the mill between the means for feeding strip to said pickling section and said pickling section for accumulating a length of strip, a pickle line exit and mill line entry looper located in the main pass line of the mill between the exit of said pickling section and the entrance of said rolling mill, and means for joining the trailing end of a coil on one end of said payoff reels with the beginning end ofa coil on the other end of said payoff reels, said pickling section, said loopers, and said end joining section all being located to one side of said pair of payoff reels, and said rolling mill section being located to the other side of said pair of payoff reels.

14. A combination pickling-rolling mill according to claim 13 wherein said conventional mill entry section is located closer to said rolling mill section than said pair of payoff reels.

15. A combination pickling-rolling mill according to claim 13 including a scale removal and trimmer section located in the main pass line of the mill between said pickle line entry looper and said pickling section, and said pickling section is located farther from said pair of payoff reels than said scale removal and trimmer section whereby the fumes from the pickling solution are easily segregated from the remainder of the mill.

16. A combination pickling-rolling mill according to claim 1 wherein said pickling section comprises a horizontally extending tank for containing pickling solution, and means for varying the location along the horizontal surface of the pickling solution at which strip is delivered into and removed from the pickling solution.

17. A combination pickling-rolling mill according to claim 16 wherein said means for varying the location at which strip is delivered into and out of the pickling sorolling mill section for the rolling of strip, a pickling section for the pickling of strip, means for feeding strip to be pickled and rolled to said pickling section, means for feeding strip from the exit end of the pickling section directly to the entry end of said rolling mill section for rolling thereof without the intervening coiling of strip, said means for feeding strip to the pickling section including a pair of payoff reels and means for alternately feeding strip from coils on said payoff reels to said pickling section, and a pickle line exit and mill line entry looper located in the main pass line of the mill between the exit of said pickling section and the entrance of said rolling mill, said looper being operable to accumulate strip when the speed of the strip being fed to said rolling mill section is slowed down such as in the case of switching of the feed of strip from said tension ireels, whereby strip is fed at a steady speed through said pickling section by the filling of said looper.

19. A combination pickling-rolling mill according to claim 1 wherein said rolling mill section comprises a tandem rolling mill including a plurality of mill stands arranged in tandem and adapted to roll strip in accordance with a predetermined group of pass schedules, and an additional mill stand included in the tandemarrangement in the rolling line, said additional mill stand being unnecessary to achieve the rolling of strip in accordance with said group of pass schedules for which the mill is designed, said mill stands being adapted to operate throughout most of the speed range of an adjacent mill so that a mill stand can be taken out of the rolling line for roll changing without interrupting the rolling action of the mill whereby said rolling mill section has a high utilization time resulting from a minimum downtime due to roll changing and also the total utilization time of the combination pickling-rolling mill is increased.

20. A combination pickling-rolling mill comprising a rolling mill section for the rolling of strip, a pickling section for the pickling of strip, means for feeding strip to be pickled and rolled to said pickling section, means for feeding strip from the exit end of the pickling section directly to the entry end of said rolling mill section for rolling thereof without the intervening coiling of strip, said means for feeding strip to the pickling section including a pair of payoff reels and means for alternately feeding strip from coils on said payoff reels to said pickling section, a pickle line entry looper in the main pass line of the mill between the means for feeding strip to said pickling section and said pickle section for accumulating a length of strip, a pickle line exit and mill line entry looper located in the main pass line of the mill between the exit of said pickling section and the entrance of said rolling mill, and side trimming shears located in the main pass line of the mill between said loopers and near one end of said'pickling section.

21. A combination pickling-rolling mill according to claim 20 wherein said side trimming shears are located in the main pass line of the mill between said pickle line entry looper and the entry end of said pickling section. l 

1. A combination pickling-rolling mill comprising a rolling mill section for the rolling of strip, a pickling section for the pickling of strip located on the entry side of said rolling mill section, means including a supply of strip to be pickled and rolled located between said pickling section and the entry end of said rolling mill section for feeding strip to be pickled and rolled from said strip supply to said pickling section in the direction away from said rolling mill section, and means for feeding strip from the exit end of the pickling section in the direction toward said rolling mill section directly to the entry end of said rolling mill section for rolling thereof without the intervening coiling of strip.
 2. A combination pickling-rolling mill according to claim 1 wherein said means for feeding strip to the pickling section includes a pair of payoff reels, and means for alternately feeding strip from coils on said payoff reels to said pickling section.
 3. A combination pickling-rolling mill according to claim 2 comprising a pickle line entry looper in the main pass line of the mill between the means for feeding strip to said pickling section and said pickle section for accumulating a length of strip.
 4. A combination pickling-rolling mill according to claim 3 including a pickle line exit and mill line entry looper located in the main pass line of the mill between the exit of said pickling section and the entrance of said rolling mill.
 5. A combination pickling-rolling mill according to claim 4 including means for joining the trailing end of a coil on one of said payoff reels with the beginning end of a coil on the other of said payoff reels, said end joining means being located in the main pass line of the mill between said pair of payoff reels and said pickle line entry looper.
 6. A combination pickling-rolling mill according to claim 5 wherein there is provided a scale removal and trimmer section located in the main pass line of the mill between said pickle line entry looper and saId pickling section.
 7. A combination pickling-rolling mill according to claim 6 wherein said scale removal and trimmer section comprises a pair of alternately operable rolls for scale breaking and skin passing.
 8. A combination pickling-rolling mill according to claim 7 wherein said scale removal and trimmer section includes two pairs of alternately operable rotary side trimming shears and two pairs of alternately operable scrap choppers.
 9. A combination pickling-rolling mill comprising a rolling mill section for the rolling of strip, a pickling section for the pickling of strip, means for feeding strip to be pickled and rolled to said pickling section, means for feeding strip from the exit end of the pickling section directly to the entry end of said rolling mill section for rolling thereof without the intervening coiling of strip, said means for feeding strip to the pickling section including a pair of payoff reels and means for alternately feeding strip from coils on said payoff reels to said pickling section, a pickle line entry looper in the main pass line of the mill between the means for feeding strip to said pickling section and said pickling section for accumulating a length of strip, a pickle line exit and mill line entry looper located in the main pass line of the mill between the exit of said pickling section and the entrance of said rolling mill, means for joining the trailing end of a coil on one end of said payoff reels with the beginning end of a coil on the other end of said payoff reels, said end joining means being located in the main pass line of the mill between said pair of payoff reels and said pickle line entry looper, and means for feeding strip in an alternate pass line from the exit end of said pickle line entry looper and bypassing said pickling section to said rolling mill section whereby fully continuous rolling is performed by the passage of strip through said alternate pass line.
 10. A combination pickling-rolling mill comprising a rolling mill section for the rolling of strip, a pickling section for the pickling of strip, means for feeding strip to be pickled and rolled to said pickling section, means for feeding strip from the exit end of the pickling section directly to the entry end of said rolling mill section for rolling thereof without the intervening coiling of strip, said means for feeding strip to the pickling section including a pair of payoff reels and means for alternately feeding strip from coils on said payoff reels to said pickling section, a pickle line entry looper in the main pass line of the mill between the means for feeding strip to said pickling section and said pickling section for accumulating a length of strip, a pickle line exit and mill line entry looper located in the main pass line of the mill between the exit of said pickling section and the entrance of said rolling mill, means for joining the trailing end of a coil on one end of said payoff reels with the beginning end of a coil on the other end of said payoff reels, said end joining means being located in the main pass line of the mill between said pair of payoff reels and said pickle line entry looper, a tension reel means, and means for diverting strip, which is being fed from the line exit and mill entry looper toward said rolling mill section, to said tension reel means for the coiling of pickled strip.
 11. A combination pickling-rolling mill according to claim 10 including means for treating strip delivered to said tension reel means.
 12. A combination pickling-rolling mill according to claim 9 including a conventional mill entry section which comprises a third payoff reel located adjacent said the entry end of said rolling mill section and means for feeding strip from a coil on said third payoff reel directly to said rolling mill for conventional batch-type rolling.
 13. A combination pickling-rolling mill comprising a rolling mill section for the rolling of strip, a pickling section for the pickling of strip, means for feeding strip to be pickled and rolled to said pickling section, means for feeding strip from the exit end of the pickling section directly to the entry end of said rolling mill section for rolling thereof without the intervening coiling of strip, said means for feeding strip to the pickling section including a pair of payoff reels and means for alternately feeding strip from coils on said payoff reels to said pickling section, a pickle line entry looper in the main pass line of the mill between the means for feeding strip to said pickling section and said pickling section for accumulating a length of strip, a pickle line exit and mill line entry looper located in the main pass line of the mill between the exit of said pickling section and the entrance of said rolling mill, and means for joining the trailing end of a coil on one end of said payoff reels with the beginning end of a coil on the other end of said payoff reels, said pickling section, said loopers, and said end joining section all being located to one side of said pair of payoff reels, and said rolling mill section being located to the other side of said pair of payoff reels.
 14. A combination pickling-rolling mill according to claim 13 wherein said conventional mill entry section is located closer to said rolling mill section than said pair of payoff reels.
 15. A combination pickling-rolling mill according to claim 13 including a scale removal and trimmer section located in the main pass line of the mill between said pickle line entry looper and said pickling section, and said pickling section is located farther from said pair of payoff reels than said scale removal and trimmer section whereby the fumes from the pickling solution are easily segregated from the remainder of the mill.
 16. A combination pickling-rolling mill according to claim 1 wherein said pickling section comprises a horizontally extending tank for containing pickling solution, and means for varying the location along the horizontal surface of the pickling solution at which strip is delivered into and removed from the pickling solution.
 17. A combination pickling-rolling mill according to claim 16 wherein said means for varying the location at which strip is delivered into and out of the pickling solution comprises a group of rollers located at both the entry and exit end of said tank, each group of rollers being linked together and movable across the pickling solution between retracted and extended positions.
 18. A combination pickling-rolling mill comprising a rolling mill section for the rolling of strip, a pickling section for the pickling of strip, means for feeding strip to be pickled and rolled to said pickling section, means for feeding strip from the exit end of the pickling section directly to the entry end of said rolling mill section for rolling thereof without the intervening coiling of strip, said means for feeding strip to the pickling section including a pair of payoff reels and means for alternately feeding strip from coils on said payoff reels to said pickling section, and a pickle line exit and mill line entry looper located in the main pass line of the mill between the exit of said pickling section and the entrance of said rolling mill, said looper being operable to accumulate strip when the speed of the strip being fed to said rolling mill section is slowed down such as in the case of switching of the feed of strip from said tension reels, whereby strip is fed at a steady speed through said pickling section by the filling of said looper.
 19. A combination pickling-rolling mill according to claim 1 wherein said rolling mill section comprises a tandem rolling mill including a plurality of mill stands arranged in tandem and adapted to roll strip in accordance with a predetermined group of pass schedules, and an additional mill stand included in the tandem arrangement in the rolling line, said additional mill stand being unnecessary to achieve the rolling of strip in accordance with said group of pass schedules for which thE mill is designed, said mill stands being adapted to operate throughout most of the speed range of an adjacent mill so that a mill stand can be taken out of the rolling line for roll changing without interrupting the rolling action of the mill whereby said rolling mill section has a high utilization time resulting from a minimum downtime due to roll changing and also the total utilization time of the combination pickling-rolling mill is increased.
 20. A combination pickling-rolling mill comprising a rolling mill section for the rolling of strip, a pickling section for the pickling of strip, means for feeding strip to be pickled and rolled to said pickling section, means for feeding strip from the exit end of the pickling section directly to the entry end of said rolling mill section for rolling thereof without the intervening coiling of strip, said means for feeding strip to the pickling section including a pair of payoff reels and means for alternately feeding strip from coils on said payoff reels to said pickling section, a pickle line entry looper in the main pass line of the mill between the means for feeding strip to said pickling section and said pickle section for accumulating a length of strip, a pickle line exit and mill line entry looper located in the main pass line of the mill between the exit of said pickling section and the entrance of said rolling mill, and side trimming shears located in the main pass line of the mill between said loopers and near one end of said pickling section.
 21. A combination pickling-rolling mill according to claim 20 wherein said side trimming shears are located in the main pass line of the mill between said pickle line entry looper and the entry end of said pickling section. 